This invention pertains to the art of inserting foldable conduits in subterranean locations. More particularly, the present invention pertains to the art of plowing in foldable arched conduits, particularly for drainage applications, beneath the surface of the soil.
Numerous plow devices have been developed for inserting circular, nonfolding conduits beneath the surface of the soil. Typically, these units included a rigid plow unit mounted at the lower end of a heavy support member. The plow unit was pulled through the soil lifting the soil sufficiently to form a cavity or trench immediately behind the plow. A tubular boot or feeder was mounted directly behind the plow to feed the circular tubing into the cavity. As the plow unit was pulled by a tractor or other heavy equipment of sufficient strength to force the plow through the soil, the soil loosened by the plow would fall by gravity around the circular conduit. The circular conduit was fed from a large reel which was mounted either on the tractor or on a separate vehicle into the boot or feeder. Because the reels held rigid circular, non-folded conduit, they were bulky, yet held a limited amount of conduit. Once the lead end of the tubing was anchored in the ground by the weight of the soil, additional tubing was pulled from the reel as the plow advanced. Various types of conduits have been plowed into the soil such as corrugated drainage tubing, natural gas lines, and the like. Typical prior art plows are shown for example in U.S. Pat. No. 4,179,227, issued Dec. 18, 1979 to James L. Child, Jr. et al., U.S. Pat. No. 3,706,207, issued Dec. 19, 1972 to Werner Cornelius et al., and U.S. Pat. No. 3,575,006, issued Apr. 13, 1971 to Roger R. Rugooden et al. A prior approach for eliminating bulky reels of non-foldable conduit is shown in U.S. Pat. No. 3,132,416, issued May 12, 1964 to James M. Hait.
The boot or feeder associated with the prior art plows are generally circular sleeves for guiding the circular tubing into the ground. The circular conduit being non-foldable, the boots or feed guides were not adapted to alter the conduit between folded and unfolded configurations. The present invention enables foldable conduits to be inserted or plowed into the soil.